1. Field of the Invention
This invention relates generally to digital data processing, and, in particular, to a human interface system in which images corresponding to multiple applications can be displayed and updated on a suitable output device simultaneously and independently of one another.
2. Description of the Related Art
It is known in the data processing arts to provide an output display in which images from multiple applications can be displayed. For example, it is known to print a portion of a spread-sheet to disk and then read such portion into a desired place in a word-processing application file. In this manner, information from one application may be incorporated into another.
However in the known technique for integrating information from two or more applications, once the output of an application was printed to disk it was "dead" information and was no longer an active part of the application. Using the example given above, the spread-sheet portion would have been fixed in time and would no longer vary with a change in one of its cells. To reflect such a change, the spread-sheet would have had to be printed again to disk and then re-read into the word-processing file.
There is therefore a significant need to be able to provide within the human interface of a data processing operating system the ability to permit information from multiple application sources to be displayed simultaneously in a live condition.